2,495 research outputs found
More than just engaging? TikTok as an effective learning tool.
With the growing popularity of social media, educators have been adopting social media platforms, such as TikTok, for learning purposes. Whilst the effectiveness of TikTok to increase learner engagement has been demonstrated, there was little evidence indicating the effectiveness of TikTok on actual learner performance through formal graded assessments. This study is one of the first attempts to investigate the effects of TikTok as a learning tool on learner performance. The findings from a controlled experiment indicate that TikTok had a beneficial impact on the learner\u27s performance as well as self-perceived engagement in an introductory statistics course
A jetlet hierarchy for ideal fluid dynamics
European Research Council Advanced Grant 267382 FCCA
Phase II Study of Gemcitabine and Docetaxel Combination in Patients with Previously Treated Recurrent or Metastatic Squamous Cell Carcinoma of the Head and Neck
Purpose. To explore the safety and efficacy of gemcitabine and docetaxel (GEMDOC) in previously treated patients with recurrent or metastatic squamous cell carcinoma of the head and neck (SCCHN). Patients and Methods. Patients with advanced SCCHN previously pretreated with one or two lines of palliative chemotherapy were treated with gemcitabine and docetaxel until disease progression. Results. Thirty-six patients were enrolled, and 29 were response evaluable. 16 (55%) experienced clinical benefit (response or stable disease). Six (21%) patients achieved partial response (PR), none achieved complete response (CR), and the overall response rate (ORR) was 21% (95% CI: 0.10–0.38). Ten (28%) patients had stable disease. The median response duration (RD) for the 6 PR patients was 3.2 months (80% CI: 2.0–6.1 months). Median overall survival was 4.2 months (95% CI: 2.4–7.0 months). Among the 33 treated patients: 13 (39%) patients had grade 3-4 anemia, 10 (30%) had grade 3-4 neutropenia. Conclusion. The study drugs were relatively safe, and the clinical benefit (PR + SD) rate was 55%. However, the efficacy objective for this regimen was not met. Given the good safety profile, further investigation of this regimen with the addition of a targeted agent may lead to better efficacy
Fluoroquinolone and Other Antimicrobial Resistance in Invasive Pneumococci, Hong Kong, 1995–2001
Fluoroquinolone resistance among invasive pneumococci in Hong Kong was high and a result of clonal expansion and spread
Transumbilical Single Port Laparoscopic Adrenalectomy: A Technical Report on Right and Left Adrenalectomy Using the Glove Port
Recently, single port laparoscopic surgery has been the focus of attention due to the advanced laparoscopic skills accumulated from experience and developments in laparoscopic instruments. Herein, we present two cases of initial single port laparoscopic adrenalectomies. Case 1 was a 38-year-old female patient diagnosed with primary hyperaldosteronism because of a the right adrenal 2.5-cm sized adenoma, and case 2 was a 31-year-old female patient diagnosed with primary adrenal Cushing's syndrome because of a left adrenal 2.9-cm sized adenoma. Both patients successfully underwent single port laparoscopic adrenalectomies via a transumbilical transperitoneal approach. There was no estimated blood loss and the total operating times were 60 and 70 minutes, respectively. Both patients recovered uneventfully. We believe that this technique presented could provide potential benefits (lesser wound pain, better cosmetic satisfaction, and shorter convalescence) if the indications are carefully selected
Weak dual pairs and Jetlet methods for ideal incompressible fluid models in n≥2 dimensions
We review the role of dual pairs in mechanics and use them to derive particle-like solutions to regularized incompressible fluid systems. In our case we have a dual pair resulting from the action of diffeomorphisms on point particles (essentially by moving the points). We then augment our dual pair by considering the action of diffeomorphisms on Taylor series, also known as jets. The augmented weak dual pairs induce a hierarchy of particle-like solutions and conservation laws with particles carrying a copy of a jet group. We call these augmented particles jetlets. The jet groups serve as finite-dimensional models of the diffeomorphism group itself, and so the jetlet particles serve as a finite-dimensional model of the self-similarity exhibited by ideal incompressible fluids. The conservation law associated to jetlet solutions is shown to be a shadow of Kelvin’s circulation theorem. Finally, we study the dynamics of infinite time particle mergers. We prove that two merging particles at the zeroth level in the hierarchy yield dynamics which asymptotically approach that of a single particle in the first level in the hierarchy. This merging behavior is then verified numerically as well as the exchange of angular momentum which must occur during a near collision of two particles. The resulting particle-like solutions suggest a new class of meshless methods which work in dimensions [Math Processing Error] n≥2 and which exhibit a shadow of Kelvin’s circulation theorem. More broadly, this provides one of the first finite-dimensional models of self-similarity in ideal fluids
Mitochondria are physiologically maintained at close to 50 degrees C
In endothermic species, heat released as a product of metabolism ensures stable internal temperature throughout the organism, despite varying environmental conditions. Mitochondria are major actors in this thermogenic process. Part of the energy released by the oxidation of respiratory substrates drives ATP synthesis and metabolite transport, but a substantial proportion is released as heat. Using a temperature-sensitive fluorescent probe targeted to mitochondria, we measured mitochondrial temperature in situ under different physiological conditions. At a constant external temperature of 38 degrees C, mitochondria were more than 10 degrees C warmer when the respiratory chain (RC) was fully functional, both in human embryonic kidney (HEK) 293 cells and primary skin fibroblasts. This differential was abolished in cells depleted of mitochondrial DNA or treated with respiratory inhibitors but preserved or enhanced by expressing thermogenic enzymes, such as the alternative oxidase or the uncoupling protein 1. The activity of various RC enzymes was maximal at or slightly above 50 degrees C. In view of their potential consequences, these observations need to be further validated and explored by independent methods. Our study prompts a critical re-examination of the literature on mitochondria.Peer reviewe
Molecular details of quinolone–DNA interactions: solution structure of an unusually stable DNA duplex with covalently linked nalidixic acid residues and non-covalent complexes derived from it
Quinolones are antibacterial drugs that are thought to bind preferentially to disturbed regions of DNA. They do not fall into the classical categories of intercalators, groove binders or electrostatic binders to the backbone. We solved the 3D structure of the DNA duplex (ACGCGU-NA)(2), where NA denotes a nalidixic acid residue covalently linked to the 2′-position of 2′-amino-2′-deoxyuridine, by NMR and restrained torsion angle molecular dynamics (MD). In the complex, the quinolones stack on G:C base pairs of the core tetramer and disrupt the terminal A:U base pair. The displaced dA residues can stack on the quinolones, while the uracil rings bind in the minor groove. The duplex-bridging interactions of the drugs and the contacts of the displaced nucleotides explain the high UV-melting temperature for d(ACGCGU-NA)(2) of up to 53°C. Further, non-covalently linked complexes between quinolones and DNA of the sequence ACGCGT can be generated via MD using constraints obtained for d(ACGCGU-NA)(2). This is demonstrated for unconjugated nalidixic acid and its 6-fluoro derivative. The well-ordered and tightly packed structures thus obtained are compatible with a published model for the quinolone–DNA complex in the active site of gyrases
Agriculture in Taiwan and South Korea: the minimalist state?
SUMMARY The state has intervened heavily in the agricultural economies of Taiwan and South Korea, both by direct administrative means and by establishing price relativities very different from those set by market forces. Although state action has not always been effective or efficient, it has played a major role in making agriculture serve the objective of rapid industrial growth. The forms and consequences of state intervention have changed over time in response to the political and economic pressures arising from structural economic change. The state has been obliged to be interventionist in order to try to maintain the political order on which continual reinvestment and thus continued growth depend. RESUMEN Agricultura en Taiwán y Corea del Sur: estado minimalista? El estado ha intervenido fuertemente en la economía agrícola en ambos países, tanto por medios directamente administrativos, como por el establecimento de precios relativos muy diferentes de aquellos derivados de la acción de las fuerzas del mercado. Aunque no siempre la acción estatal ha sido efectiva o eficiente, ha jugado un rol principal para que la agricultura sirva los objetivos de un rápido crecimiento industrial. Las formas y consecuencias de la intervención estatal han cambiado a través del tiempo, como respuesta a las presiones económicas derivadas del cambio en la estructura económica. El estado se ha visto obligado a ser intervencionista para tratar de mantener el orden politico del cual depende la continua reínversíón y, en consecuencia, el crecimiento persistente. RESUMES L'agriculture à Taiwan et en Corée du Sud: l'état minimaliste? L'état a intervenu de façon très importante dans les économies agricoles de Taiwan et de la Corée du Sud, par des moyens administratifs directs et en établissant une relativité des prix très différente de celle établie par les forces de marché. Quoique l'action de l'état n'ait pas toujours été effective ou efficace, elle a joué un rôle de grande importance en se servant de l'agriculture pour aider une croissance industrielle rapide. Les formes et les conséquences de l'intervention de l'état ont changé au cours des temps en fonction des pressions politiques et économiques provenant du changement de la structure économique. L'état a été obligé d'être interventionniste de façon à essayer de maintenir l'ordre politique duquel dépendent le rèinvestissement continu et donc la croissance continue
Pacemaker Lead Endocarditis Caused by Achromobacter xylosoxidans
We report the case of a 35-yr-old patient who presented with high fever and chills. He had undergone a patch closure of the ventricular septal defect 18 yr before. One year later, a VVI pacemaker was implanted via the right subclavian vein because of complete heart block. Nine years after that, a new VVI pacemaker with another right ventricular electrode was inserted controlaterally and the old pacing lead was abandoned. Trans-thoracic and trans-esophageal echocardiogram identified the pacemaker lead in the right ventricle (RV) attaching hyperechoic materials and also a fluttering round hyperechoic mass with a stalk in the RV outflow tract. Cultures in blood and pus from pacemaker lead grew Achromobacter xylosoxidans. A diagnosis of pacemaker lead endocarditis due to Achromobacter xylosoxidans was made. In this regards, the best treatment is an immediate removal of the entire pacing system and antimicrobial therapy
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